Reactive oxygen species and the neurodegenerative disorders.

The major neurodegenerative disorders include Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and multiple sclerosis. Although their etiology and pathogenesis are unknown, numerous recent studies suggest that oxygen-derived free radicals play an important role. Furthermore, these reactive oxygen species are probably important in brain ischemia and reperfusion, Down's syndrome, and the mitochondrial encephalopathies. In this review, evidence for oxygen-derived free radicals in the pathogenesis of these disorders is discussed.